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Item Challenges in the Digitisation of a High-reflective Artwork(The Eurographics Association, 2021) Catalano, Chiara Eva; Brunetto, Erika; Mortara, Michela; Pizzi, Corrado; Hulusic, Vedad and Chalmers, AlanIn this paper we report about the photogrammetric acquisition and reconstruction of a contemporary artwork, performed by offthe- shelf software. The ceramic piece of art is "Il Libro d'Oro del Terzo Paradiso" ("The Golden Book of the Third Paradise") by Michelangelo Pistoletto, accessed and studied in the framework of a regional project. This artefact is particularly challenging. On the one hand, it is golden coated and, as such, highly reflective. Hence, images are likely to suffer from highlight spots, shadows or self-reflections, and the reconstructed point cloud is typically noisy. On the other hand, the object exhibits simple geometry, mainly composed of planar surfaces, and is highly symmetric; however, it possesses detail features and undercuts. The symmetric nature of the object and reflections misled the image alignment, and the noise in the data turned out to be of the same scale as the detail features. We will discuss all the steps of the process, aimed at obtaining a high quality and accurate 3D model using low-cost tools.Item Virtual Dance Museum: the Case of Greek/Cypriot Folk Dancing(The Eurographics Association, 2021) Aristidou, Andreas; Andreou, Nefeli; Charalambous, Loukas; Yiannakidis, Anastasios; Chrysanthou, Yiorgos; Hulusic, Vedad and Chalmers, AlanIn this paper, we have designed and developed a virtual dance museum to provide the technological tools that allow for widely educating the public, most specifically the youngest generations, about the story, costumes, music, and history of our dances. The holistic documentation of our intangible cultural heritage creations is a critical necessity for the preservation and the continuity of our identity as Europeans. In that direction, we have employed a specially designed relational database schema that holistically structures the information within the database, and is ideal for archiving, presenting, further analyzing, and re-using dance motion data. Data have been retargeted to a virtual character, dressed with traditional uniform and simulated to achieve realism. The users can view and interact with the archived data using advanced 3D character visualization in three ways: via an online 3D virtual environment; in virtual reality using headset; and in augmented reality, where the 3D characters can co-inhabit the real world. Our museum is publicly accessible, and also enables motion data reusability, facilitating dance learning applications through gamification.Item A Massively Parallel CUDA Algorithm to Compute and Visualize the Solvent Excluded Surface for Dynamic Molecular Data(The Eurographics Association, 2019) Schäfer, Marco; Krone, Michael; Byska, Jan and Krone, Michael and Sommer, BjörnThe interactive visualization of molecular surfaces can help users to understand the dynamic behavior of proteins in molecular dynamics simulations. These simulations play an important role in biochemical and pharmaceutical research, e.g. in drug design. The efficient calculation of molecular surfaces in a fast and memory-saving way is a challenging task. For example, to gain a detailed understanding of complex diseases like Alzheimer, conformational changes and spatial interactions between molecules have to be investigated. Molecular surfaces, such as Solvent Excluded Surfaces (SES), are instrumental for identifying structures such as tunnels or cavities that critically influence transport processes and docking events, which might induce enzymatic reactions. Therefore, we developed a highly parallelized algorithm that exploits the massive computing power of modern graphics hardware. Our analytical algorithm is suitable for the real-time computation of dynamic SES based on many time steps, as it runs interactively on a single consumer GPU for more than 20 k atoms.Item Pairwise Matching of Stone Tools Based on Flake-Surface Contour Points and Normals(The Eurographics Association, 2017) Xi, Yang; Matsuyama, Katsutsugu; Konno, Kouichi; Tobias Schreck and Tim Weyrich and Robert Sablatnig and Benjamin StularStone tools constitute the main artifacts facilitating archaeological research of the Paleolithic era. The reassembly of stone tools is the most important research work for analyzing human activities of that period. In recent decades, large numbers of methods have been presented to solve various registration or matching problems for point clouds; however, few methods have been successfully applied to the matching of flakes, a type of stone tool. Therefore, we propose a new matching method for studying stone tools to improve archaeological research. Our method processes pairwise matching of stone tools based on contour points and mean normals of regions on all flake surfaces, according to the characteristics of the flake models. The sample experiments conducted in this study indicate that our new method achieves superior matching results for flakes, compared with the existing methods.Item New Haven Building Archive: A Database for the Collection, Study, and Communication of Local Built Heritage(The Eurographics Association, 2018) Rubin, Elihu; Akhtar, Saima; Brown, Benedict; Rushmeier, Holly; Sablatnig, Robert and Wimmer, MichaelThe New Haven Building Archive (NHBA) is a digital, mobile, and interactive field guide to New Haven, Connecticut's built heritage. As an interactive digital guide and database for local buildings, the NHBA harnesses digital mapping technologies, place-based storytelling and community-based research. Ultimately, the development of the NHBA will aid in the co-production of knowledge about the city by students, academic researchers and local citizens in a way that will facilitate conversations about the historical patterns and future development of New Haven while suggesting a model for engaged teaching and research for urban studies more broadly.Item User-reconfigurable CAD Feature Recognition in 1- and 2-topologies with Reduction of Search Space via Geometry Filters(The Eurographics Association, 2019) Corcho, Juan Camilo Pareja; Acosta, Oscar Mauricio Betancur; Ruiz, Oscar E.; Cadavid, Carlos; Casas, Dan and Jarabo, AdriánIn the context of Computer-Aided Design and Manufacturing, the problem of feature recognition plays a key role in the integration of systems. Until now, compromises have been reached by only using FACE-based geometric information of prismatic CAD models to prune the search domain. This manuscripts presents a feature recognition method which more aggressively prunes the search space with reconfigurable geometric tests. This reconfigurable approach allows to enforce arbitrary confluent tests which are topologic and geometric, with enlarged domain. The test sequence is itself a graph (i.e. not a linear or total-order sequence). Unlike the existing methods which are FACE-based, the present one permits combinations of topologies whose dimensions are 2, 1 or 0. This system has been implemented in an industrial environment. The industrial incarnation allows industry-based customization and is faster when compared to topology-based feature recognition. Future work is required in improving robustness of search conditions and improving the graphic input interface.Item A Web-based Visual Analytics Application for Biological Networks(The Eurographics Association, 2020) Krone, Michael; Dräger, Andreas; Cobanoglu, Ebru; Harke, Manuel Otto; Hoene, Miriam; Weigert, Cora; Lehmann, Rainer; Byška, Jan and Jänicke, StefanModern high-throughput methods enable rapidly obtaining transcriptomics data, which includes information about the expression rate of genes. The expression rates are usually given as fold change, which describes the over- or under-expression of each gene. Each gene can be part of one or more biological pathways. A pathway models the interactions between molecules in an organism that lead to a particular chemical change. Consequently, many applications in medical research need to analyze the impact of gene expression changes on the biological pathways of an organism. It allows concluding diseases or other conditions of the organism. We present a web-based visual analytics application that facilitates exploring the network of biological pathways corresponding to a given set of genes. The network is constructed from pathways derived from an external database. Users can interactively zoom and filter the network and get details on demand. Our application is currently work in progress and is developed in close collaboration with medical researchers. In subsequent steps, we strive to add more features, such as the ability to compare data from different individuals or to visualize time series data. Furthermore, we want to extend our application to visualize not just transcriptomics but multi-omics data.Item Cylindrical Transform Slicing of Revolute Parts with Overhangs for Laser Metal Deposition(The Eurographics Association, 2022) Montoya-Zapata, Diego; Moreno, Aitor; Ortiz, Igor; Ruiz-Salguero, Oscar; Posada, Jorge; Posada, Jorge; Serrano, AnaIn the context of Laser Metal Deposition (LMD), temporary support structures are needed to manufacture overhanging features. In order to limit the need for supports, multi-axis machines intervene in the deposition by sequentially repositioning the part. Under multi-axis rotations and translations, slicing and toolpath generation represent significant challenges. Slicing has been partially addressed by authors in multi-axis LMD. However, tool-path generation in multi-axis LMD is rarely touched. One of the reasons is that the required slices for LMD may be strongly non-developable. This fact produces a significant mismatch between the tool-path speeds and other parameters in Parametric space vs. actual Euclidean space. For the particular case of developable slices present in workpieces with cylindrical kernel and overhanging neighborhoods, this manuscript presents a methodology for LMD tool path generation. Our algorithm takes advantage of existing cylindrical iso-radial slicing by generating a path in the (?, z) parameter space and isometrically translating it into the R3 Euclidean space. The presented approach is advantageous because it allows the path-planning of complex structures by using the methods for conventional 2.5-axis AM. Our computer experiments show that the presented approach can be effectively used in manufacturing industrial/mechanical pieces (e.g., spur gears). Future work includes the generation of the machine g-code for actual LMD equipment.Item Learning to Trace: Expressive Line Drawing Generation from Photographs(The Eurographics Association and John Wiley & Sons Ltd., 2019) Inoue, Naoto; Ito, Daichi; Xu, Ning; Yang, Jimei; Price, Brian; Yamasaki, Toshihiko; Lee, Jehee and Theobalt, Christian and Wetzstein, GordonIn this paper, we present a new computational method for automatically tracing high-resolution photographs to create expressive line drawings. We define expressive lines as those that convey important edges, shape contours, and large-scale texture lines that are necessary to accurately depict the overall structure of objects (similar to those found in technical drawings) while still being sparse and artistically pleasing. Given a photograph, our algorithm extracts expressive edges and creates a clean line drawing using a convolutional neural network (CNN). We employ an end-to-end trainable fully-convolutional CNN to learn the model in a data-driven manner. The model consists of two networks to cope with two sub-tasks; extracting coarse lines and refining them to be more clean and expressive. To build a model that is optimal for each domain, we construct two new datasets for face/body and manga background. The experimental results qualitatively and quantitatively demonstrate the effectiveness of our model. We further illustrate two practical applications.Item Subdivision Schemes With Optimal Bounded Curvature Near Extraordinary Vertices(The Eurographics Association and John Wiley & Sons Ltd., 2018) Ma, Yue; Ma, Weiyin; Fu, Hongbo and Ghosh, Abhijeet and Kopf, JohannesWe present a novel method to construct subdivision stencils near extraordinary vertices with limit surfaces having optimal bounded curvature at extraordinary positions. With the proposed method, subdivision stencils for newly inserted and updated vertices near extraordinary vertices are first constructed to ensure subdivision with G1 continuity and bounded curvature at extraordinary positions. The remaining degrees of freedom of the constructed subdivision stencils are further used to optimize the eigenbasis functions corresponding to the subsubdominant eigenvalues of the subdivision with respect to G2 continuity constraints. We demonstrate the method by replacing subdivision stencils near extraordinary vertices for Catmull-Clark subdivision and compare the results with the original Catmull-Clark subdivision and previous tuning schemes known with small curvature variation near extraordinary positions. The results show that the proposed method produces subdivision schemes with better or comparable curvature behavior around extraordinary vertices with comparatively simple subdivision stencils.